Oil-well jack



March 31, 1925. 1,531,802:

D. H. MccRAY OIL WELL JACK Filed March 17. 1924 IN VENTOR Patented Mar. 31, 1925.

UNITED STATES :DAVID H. Moon-AY, or TULSA, oKLAnoMA. I

OIL-WELL JACK.

Application filed `March l?, 1924. Serial No. Y699,667.

To all whoa/u, t may concern.'

Be it known that I, DAVID H. MCCRAY, a citizen of the United States, residing at Tulsa, in the county ot' rl'ulsa :and State of Oklahoma, have invented certain new and useful Improvements in Oil-Tell Jacks; and I do declare the following to be -a full, clear, .and 'exact ydescription :of the invention, such as will enalole vothers skilled in the art to which it appertains to inake and use the same, reference being had to the .acc-onipanying drawings, and to the figures of reiteren'ce marked thereon, which for/1n a part ot this specification.

This invention relates to oil well jacks known in the oil lield nomenclature as Barrett jacks and it conforms generically to the general construction shown in the patent to J. Barrett, No. 5:27 ,1102, patented Ootooer 9, 1894i. Such jacks are extensively used the oil iel'ds for screwing and unscrewing or jointing and disjointing tools used in oil well drilling in the. so-called standard or reciprocatory ldrilling method.

In actual practice it has heen found that while the so-called Barrett jack is ra very efficient apparatus for jointing the tools and the like, difficulty is experienced in .disjointi-ng or unscrewing. The generally accepted reason tor this is that the' tools hecorne stuck or frozen during the drilling operation yand inasmuch `as 'the full power of the jack is used Jfor Iscrewing up 'the tools, there is Vno' reserve power llett for unscrewing thorn.

lu other words, the power required to unsere/w lhe' tools the power use-d ifor screwing them together plus the power required to o'x'erconiie the lfrictfioual resistance `or @tendency to slick. v

The problem then is not `merely to pro vide a 'j ack ot great power but in order 'to have the jack operate successfully, i-t must have a disj-ointin'g power in excess of the jointing power so have provide-'d means Afor varying' the power hy providing a ulcruni for the socket lever which will he adequate to join the vtools and in addition l have provided means l'or varying the fulcrurn of the socket lever so that the ulcruin will :cause a greater multiplication of the applied power 'for unscrewingV or disjointing thein than will -loe applied for joining yor screwing the tool sections.

The novel inann'er in which the desired result .is obtained will he app-arent hy retn erence to the following description in connection with the :accoinpanyng drawings, in which- Fig. l is a perspective View of a jack `constructed in accord-ance with my invention. y

Fig. 2 is a cross sectional view through the traveler showing the power applying mechanisin in elevation, part of the socket lever being shown in section. I

Fig. 3 is a disassociated' perspective view of the fulcruni and the lookin-g lever. I

Fig. 4; is a perspective view of the clip for the locking lever.

Fig.. 5 is la detail view socket lever and fthe power-applying disk with the ulcruni in one position.

Fig. 6 isa similar view with the ulcrum in another position., and i Fig. 7 is a detail perspective view of one end of the traveler, showing the wrench@ receiving seat and the ulcr-uin seats.

l designates 4a rack, 2 the wrench post and 3 the traveler or traveling `carriage provided with the wrench socket 4. Thev traveling carri-age has two pawls or dogs 5 andl 6 to engage the rack teeth 7. These .dogs or pawls are connected to the reversinglever 8 hy the links 29 .and 110, the reversing llever being controlled by :a triplfever l1.

All of this mechanism is old well known lout instead'fof connecting the dogs to .the socket lever :as .is the usual practice, I connect Athem to a. rocking :actuator 1Q, in the forni otla gea-red disk. 'The actuator l2 has 4a .po-rtionol:` its periphery provided with teeth 13, which mesh with teeth 14 on the end ol" the socket lever 155.

\ The socket lever moui-ited on a variabile .li-ilcrun'i Y136 which constitutes the inil'yortant part ot niy invent-ion. The fulcruin lo Aconsists of atransverse 'rod 'having traces 17 and 18 so-that the rod 'lf Vis of less width across the tlat faces than the narrow portionlQ of the slot "20 in .the socket lever 15. The s101320 has two substantially cir-- cular portions '21 and 22, which constitute bearings .resting on the journal or tule-ruin lf, the edges of which are round, :as at 2,3-

The slot 2O corresponds vto similar slots 25 and 26 in the vsides of the traveler `or carriage 3 so that the tulcruin journal lo may v'loe turned in v'the position shown in Fig. 5 ito 'move it from one end'oti'the slots 20, 25 and '26 to vary .the iiulcr-uln fotthe of one end. ofthe i clip socket lever 15, it being obvious that when the journal 16 is in the rounded portion 22 ot' the slot 2O and in the lower portions of the slots 25 and 26, greater power will be exerted upon the actuator 12 than when it is in the portion 21 oif the slot 2O and the upper portions of the slots 25 and 26.

It will be observed that the journal 16 has a collar 27 at one end which bears against the side wall of the hollow carriage or carrier 3. The opposite end ot the journal or fulcrum 16 is provided with a constricted porti-on 28, projecting through the side 29 ot' the carriage and it is also provided with an opening 30 through which a bolt 31 may pass to fasten the bifurcated end 32 of the locking lever 33 to the 'fulcrum, the bolt being provided with the usual nut 34:.

The locking lever 33 extends on the outside of the carriage or carrier and it is adapted to be held against swinging movement by the U-shaped spring clip 35, which is secured to the side of the carriage 3.

It the device is being used for vscrewing up the tools or joining them, the member 16 will be in the position shown in Fig. 6. Ample power will be provided for rocking the actuator 12 so that' the dogs can perform in the usual way. Vhen it is desired to unscrew or disjoint the tools, the handle 33 will be disengaged from the 35 and the parallel flat sides 17 and 18 of the members 16 will be turned at right angles to the position shown in Fig. 6 so that the ulcrum can be moved to the position shown in Fig. 5. Then the handle is swung back to cause the parallel iiat sides 17 and 18 to assume substantially the positions shown in Fig. 6, but by this time the ulcrum will be in the portion 22 of the slot 20. ASince the tulcrum will be nearer the toe or lower end ot' the socket lever 15 than when the tulcrum is in the portion 21 ot the slot 20, it will be apparent that the same amount ot power applied to the socket lever will cxert a greater force on the wrenches, quite enough tov make up the difference between the amount of power applied in screwing up the tools plus the tendency of the parts vto adhere so that the jointed connections cepted explanation is that the jack cannot` exert su'liicient' power to break the joint or disconnect 'the tools after they have been screwed together and used. Therefore, the importance of varying the fulcrum for the socket lever will at once become apparent.

Wvhat I claim and desire to secure by Letters Patent is:

1. In an oil well jack .including a rack, a carriage, a mechanism for propelling the carriage over the rack, an actuator for the propelling mechanism including a geared member, a socket lever or actuating geared member, and a variable tulcrum for the socket lever adjustably mounted in the carriage.

2. In an oil well jack including a rack, a carriage, a mechanism` for propelling the carriage over the rack, an actuator tor the propelling mechanism including a geared member, a socket lever or actuating geared member, and a variable fulcrum for the socket lever adjustably mounted in the carriage, the fulcrum consisting of a member longitudinally movable with respect to the socket lever.

3. An oil Well jack comprising a rack, a traveling carriage on the rack forA actuating a Wrench, a pivoted disk in the carriage, dogs actuated by the disk for intermittently engaging the rack, a dog rever-sing mechanism carried by the carriage, a socket lever having an elongatedslot With a constricted intermediate portion, and a fulcrum journal movable through the constricted portion of the slot to either end thereof, the journal being mounted in slots in the sides' of the carriage similar to the slots in the socket lever.

4. An oil well jack comprising a rack, a traveling carriage on the rack for actuating a Wrench, a pivoted disk in the carriage, dogs actuated by the disk for intermittently engaging the rack, a dog reversing mechanism carried by the carriage, a socket lever having an elongated slot with a constricted intermediate portion, a lulcrum journal movable through the constricted portion of the slot to either end thereof, the journal being mounted in slots inthe sides of the carriage similar to the slots in the socketv lever, and a locking lever on one end of the journal outside the carriage for manipulating it from one end of each slot to the opposite end thereof.

5. An oil well jack comprising a rack, a traveling carriage on the rack for actuating a wrench, a. pivoted disk in the carriage, dogs actuated by the disk for intermittently engaging the rack, a dog-reversing mechanism carried by the carriage, a socket lever having an elongated slot with a constrictedy intermediate portion, a Jfulcrum journal movable through the` constricted portion of the slot to either end thereof, the journal being mounted in slots in the sides of the carriage similar to the slots in the socket lever, and a locking lever on one end of the journal outside the carriagel for manipulatine it from one e-ndof each slot to the opposite end thereof, said locking lever being' pivoted to the journal.

6. An oil Well jack comprising ay rack, a

traveling' carriage on the rack for actuating a Wrench, a pivoted dis-k in the carriage, dogs actuated by the disk for intermittently engaging the rack, a dog-reversing mechanism carried by the carriage, a socket lever having an elongated slot with a constricted intermediate portion, a fulorum journal movable through the oonstrioted portion of the slot to either end thereof, the journal being mounted in slots in the sides of the carriage similar to the `slots in the socket lever, a locking lever on one end of the journal outside the carriage for manipulating it from one end of each slot to the opposite end thereof,` said llooking lever being pivoted to the journal, and a'elilo'A on the side of the carriage for holdingfthe locking lever in :normal position.

In testimony whereof I aix my signature.

DAVID H. MCGRAY. 

